


Ben and Gwen's Kinky Adventures

by Ira94



Category: Ben 10 Series
Genre: Big Breasts, Come Inflation, Cousin Incest, F/F, F/M, Femdom, Futa on Male, Genderbending, Inflation, M/M, Male Lactation, Male with Breasts, Mpreg, Other, Transformation, Weight Gain, all kinds of kinky things, expansion
Language: English
Status: In-Progress
Published: 2020-03-23
Updated: 2020-03-23
Packaged: 2021-02-28 21:40:27
Rating: Mature
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 1
Words: 4,427
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/23274127
Author URL: https://archiveofourown.org/users/Ira94/pseuds/Ira94
Summary: This is a story of the many hot and erotic adventures of Ben and Gwen, ranging from all kinds of kinks and fetishes to your delights.
Relationships: Ben Tennyson/Gwen Tennyson
Comments: 6
Kudos: 54





	Ben and Gwen's Kinky Adventures

It was just another day for young Ben 10 and his cousin Gwen and his Grandpa Max as they drove across America going on crazy adventures.

Ben himself had never felt cooler or more in control ever since he got the insane power of the Omnitrix that gave him the power to change into an alien at will.  
But the Omnitrix it's self while very useful was also very glitchy and hard to use since it was unknown alien tech. Ben sometimes struggled to use the device but one day while Ben and his family where at a water park Ben ran into a small problem. "Damn stupid watch would you stop glitching out?" Ben said in frustration as he messed with the Omnitrix.

He then heard Gwen say "Hey stupid what are you doing? I thought you wanted to go in the pool?

"It's this damn watch it's acting up again." Ben showed Gwen the device and Gwen looked at Ben confused as she said "What's that symbol supposed to mean?"

Ben looked down and saw the symbols that showed what alien he would choice was kind of different...he looked at the symbol and saw what kind of looked like boobs?

"What the heck does this do? Ben questioned.

Gwen shrugs "Maybe it's a new alien try it out."

Ben decided to go into the pool locker rooms to see what his new power did. he pressed the button expecting a cool new alien but when he pressed it nothing happened. "Stupid thing's broke..." but as he stared at his watch something odd happened he felt his chest become heavier and more sensitive. He looked down and to his shock his chest was growing into a big pair of womanly boobies! He grabbed his growing boobs in shock wanting it to stop but they just kept growing bigger.

By the time Ben's new tits where done growing they where the size of beach balls!

Ben was blushing in embarrassment, he had just grown breasts the size beach balls. He wanted to scream but that would just draw attention to himself. Right now Ben didn't want anyone to see him like this, especially not Gwen. She'd tease him to no end.

Ben needed to fine something to cover himself, while he looked around his trunks got caught on something. Panicking he tried to get them free, but Ben pulled to hard causing them to ripe apart. Ben cursed, he was now completely naked. He had to fine some clothes and fast. He search the locker room and he found...a bright green two piece bikini that was just big enough to fit him. Ben gulped finding it super embarrassing but it was this or nudity. So Ben swallowed his pride and began to get dressed. He pulled up the bikini bottom over his small ass and junk.

Then came the hard part. As Ben began to wrap the bikini top around his tits. It was so small for his massive tits that Ben was struggling to get the thing to fit. The top was so tight and squished into his tit flesh making Ben feel tight. His bikini top strained around his boobs and at last he got it on. Ben sighed in annoyance the bikini top was so small it only could cover his nipples so it didn't cover Ben's massive boobs too much but...it was better then nothing.

But, while Ben looked at his lewd body he heard people coming. A bunch of boys saw Ben and where shocked by his massive boobs. Ben had to get out of here , he saw the looks the boys where giving him. They frightened him , so he pull through them. This had a side effect of cashing Ben's new big juicy boobs. As Ben run pass the boys and out of locker room , he continue to run people stared at him.

Ben blushed as he felt so embarrassed by the many eyes that followed him as his knockers bounced wildly, he needed to fine a place to hide. Soon he saw some building, he hides behind it. Ben panted as he leans against the wall, his breasts lightly bouncing from his breathing. As he rested he try to figure what should he do next, then he heard someone behind him.

"Ben? Is that you?"

' _Shit!_ ' Ben quickly turned making his massive tits swing around and hit the person behind him knocking them over. Ben looked down past his huge boobies and saw Gwen rubbing her head on the floor. Ben bends down saying "Oh god, Gwen are you ok?"

Gwen rubs her head and looks up to her cousin. "Am I ok? What the hell happened to you?" She questioned as her view was taken up by Ben's dangling boobs that looked so large and heavy, Ben suddenly lost balance and fell over on top of Gwen squishing her face between his big boobs.

Ben blushed as he tried to get off but Gwen flipped him around so now she was on top. Ben felt like he had no control as the combined weight of Gwen and his boobies kept him pinned to the floor. Both cousins seemingly stared into each others eyes while Ben blushed and looks away, still embarrassed by the fact that Gwen of all people saw him with a massive pair of breasts. ' _Oh god, this is so embarrassing!_ ' Ben inwardly cried out in dismay. Then he let out a yelp when he felt a pair of hands on his breasts. He looks down and saw it was Gwen whose hands were on his melons, making him blush ten fold.

Gwen looked flustered as she stared at Ben's boobs, her hands could feel the firm and soft orbs that are her cousin's boobs. Gwen didn't know why she just didn't remove her hands from Ben's tits, but she couldn't. They felt so warm and soft, she was blushing thinking who wonderful they where. She licked her lips and began to play with them.

Ben gasped when he felt a shiver coursing through his spine, as Gwen played with his tits, he bit his lips so not to moan. Gwen squeeze Ben's tits which caused Ben to moan a little. Gwen suddenly found herself loving the sound of Ben moaning, she wanted to hear more.

"You like this Ben? You like when someone plays with your nice, big, juicy tits?" Gwen said in a coy tone with a smirk.

Ben gulped he didn't know what to do, he wanted Gwen to stop but he enjoy the feeling of her playing with his tits. ' _Oh, shit! W-Why does this feel so good all of a sudden? I want her to get off me, to try and find a way to get rid of these things...and yet I don't want her to stop!_ '

As Gwen continued playing and squeezing Ben's tits, she was enjoying it. She wanted to continue all summer long , she wanted Ben as her slave. Gwen stopped and gets off of Ben.

Ben was panting softly from Gwen fondling his boobs and looks up to see her hand stretched out. "Come on. We're taking this somewhere private." She said.

He looks at her in confusion and slight worry, but he reached out and felt her pulling him up and quickly dragged him off out of sight, passing by the many patrons while keeping an eye out for their grandfather. When they made their way through the crowd they spotted Max sitting on a lounge chair sleeping, which made Gwen smile. ' _Perfect._ '

"Wait, where are we-"

"We're heading for the RV, grandpa's sleeping, so we'll have plenty of time alone to ourselves~" she grinned with a seductive tone as she pulled Ben quicker to the RV.

They eventually made it to the RV Gwen was the first to go in, and pulls Ben inside and locks it.

"Uh, Gwen, maybe we...mph!" Ben was cut off when Gwen rams her lips against his and pinning him against the door, while using one hand to stroke his face, the other went for his left boob. He blushed bright red while moaning at the sudden grab as she didn't wait and began to squeeze and massage it.

Both cousins moaned together while Gwen moved her leg in between Ben's legs, nudging his limp member which was growing hard under the bikini. Gwen slowly breaks the kiss with saliva connected between them while they panted for much needed air.

"...G-Gwen...w-why did you..." He was silenced when she placed a finger on his lips.

"Let's just say that...I had this major crush on you for a very long time." She answered with her smile never leaving her face.

"W...What?" let out Ben with wide eyes while Gwen got up.

"And since the cat's out of the bag, no sense in taking things slow."

She pulls Ben all the way back while with a snap of her fingers, her magic closed the shades around the RV, making sure no one would see them.

Ben found himself being thrown on the couch at the far back, and gasped when the bikini was ripped to shreds and revealed his 11 inch hard on cock.

"Wow, you even got hard from all that. Looks like you're a real perv."

"S-Shut up!" Ben stuttered with his face bright red.

Gwen only smiled wider as she strips herself of her swimsuit, she crawls over Ben till she's nose-to-nose with him. "There's no need to be so embarrassed. I think you look way better with these~" She said while patting his breasts.

Ben watched as Gwen moved to his left boob and yelped when she latched onto his nipple and began to suck on it.

"H-Hey! D-Don't suck on it!"

Gwen didn't listen as she kept on sucking on his nipple, teasing the nub with her tongue until she felt something spraying into her mouth.

' _Wait, is this-_ ' Gwen sucked harder which made Ben moan out as his other nipple suddenly squirted milk! ' _Holy cow! He can make milk too?_ '

Even Ben was shocked to see milk flying from his right boob, Gwen however took an instant liking to his milk and sucked harder on his nub, making him throw his head back and moaned. "Gwen!"

Gwen continued to drink from Ben's tit while reaching for his other boob and plays with it, resulting more milk to spray out, she then pulls away from the nipple she was on and latched onto the other one while reaching down to play with Ben's cock. "Gwen!" moaned Ben louder with his dick growing harder.

Gwen then pulls away from the nipple and rams her lips against his, wanting him to taste his own milk. Ben moaned and tried kissing back as hard as possible.

Gwen pulls away from the kiss and held Ben in her arms, panting from the kiss, she then lays back down and spreads her legs open revealing her nether lips.

"Go ahead Ben. Take me before I claim you~"

Ben gulped when he saw her soaked folds and felt his dick throb in eager. He slowly moves over to her, aligns his member at her lips and pushes it in, they groaned in unison as Ben continued to push his cock inside her, her insides were so tight it felt like he was trying to put a ring on.

"F-Fuck!" cursed out Gwen.

Ben kept pushing until he reached Gwen's hymen. "G-Gwen...a-are you sure about this?"

Gwen slowly nods. "Yes, go ahead and fuck me, Ben~"

"Isn't it gonna hurt?"

"That's how it is for first-timers. But enough about that, please fuck me Ben, I've waited long enough for this."

"Do you want me to move fast?" Ben questioned.

Gwen slowly nods and reached out to wrap her arms around his neck, and brought him close to her. "Do it. Make me feel good." She said in his ear before bracing herself for what's to come.

"Alright, you asked for it." He warned her. Then taking a deep breath he plunges his cock deep inside Gwen, tearing through her hymen and felt her hold on him tightening up as she gritted her teeth with tears falling, and blood oozing out.

"AHHHH!" Gwen cried out as she hugged Ben tighter while gritting her teeth. She knew that this was the first step of entering the world of adulthood, but she never imagined it'd hurt this much. "Ow, ow, ow, ow, ow!" Gwen grunted while she felt Ben rubbing her back.

"I'm sorry Gwen." He apologized.

"D-Don't be! I knew it would hurt like this, and I don't have any regrets!"

"Should I start moving?"

Gwen nods. "Y-Yeah, but go slow so I can get used to the pain."

"You got it." Ben slowly pulls his cock out and pushes it back while Gwen lightly moaned when her insides were molding around Ben's cock, slowly getting used to his member.

"T-That's it, right there." Gwen groaned while moving her hands to play with Ben's breasts, urging him to speed up a little.

Ben gasped when he felt Gwen's hands running on his boobs which made him pick up speed, both cousins lightly moaned and panted as the pain immediately vanished from Gwen and being replaced by pleasure.

"Oh god yeah!" Gwen groaned while pinching Ben's nipples making him yelp rather girlishly and rams his hips against her, she felt herself being pinned by his breasts which nearly pushed her in between them and found herself being kissed by Ben. ' _Oh fuck is this hot!_ ' Gwen inwardly exclaimed while their tongues tangled with each other.

As Ben continued kissing her he let out a muffled yelp when Gwen grabbed his ass checks and kneaded them like dough. ' _I can't believe I'm actually fucking my cousin!_ '

Gwen then breaks the kiss and pushes Ben back till he's laying on the couch with her straddling him. "F-F-Fuck, Gwen! Is...Is this how you really felt about me?" He questions while thrusting his hips upward and his boobs played with.

"Yes! You have no idea!" Gwen exclaimed while bouncing wildly on Ben. "It took every ounce of self control I had just to keep myself from raping you, I wanted you to be mine so bad! But now that you've gained breasts of your own I finally have you all to myself!" Gwen bounced and bounced harder on Ben's dick, while pinching and twisting his nipples to the point where milk was spraying all over them, Ben moaned loudly as he felt his climax reaching its limit.

"Gwen! I'm gonna lose it!"

"Go ahead! Shoot it in me, give me your hot spunk!"

"AHHHHH!" Both of them cried out in unison as Ben explodes inside Gwen, filling her up with his seed and his milk spraying everywhere. They gritted their teeth while blown away at the orgasmic feeling. After what felt like forever Gwen slowly pulls herself off Ben's cock, letting some of the sperm ooze out and collapsed onto his bust, cushioning her like a pillow. Both panted with flushed expressions while feeling drained.

"...W-Wow...That was...wow." Ben breathed out.

"I...I know...It was amazing for me too." Gwen panted while nuzzling into Ben's boobs.

"Mmm...these are great for pillows." Gwen purrs while rubbing her hands on the smooth skin that is Ben's boobage. After a minute or two she gets up and walks away from Ben, which made him raise his brow as he sat up. "I got a little surprise for you Ben but you gotta turn around first." She said with a saucy smile.

Ben blinks a few times before doing as she asked and turns around. 'I wonder what exactly she has in store? I hope it's nothing too embarrassing.' He though to himself only to be broken from his train of thought as he felt something poking his head.

"You can turn around now Ben~"

He did so and when he did his eyes nearly bulged out when he saw Gwen, with a very large and long veiny cock of her own, with a huge pair of balls to go with!

"Now it's YOUR turn to get the D." Gwen smirked while wagging her huge cock at Ben's stunned face.

"...G-G-Gwen!? W-Where'd you..." Ben stutters and felt the cock being pushed to his face.

"I found a spell on my book that allows me to have my own cock and balls." Gwen explains while nudging her newly acquired member in his face. "I'd start sucking on it now Ben, before I FORCE feed it to you!"

"B-But that's-MMMPH!" Ben was cut off when Gwen shoves her cock in his mouth, almost gagging when it hit the back of his throat.

"Ben...shut up and start sucking!" Gwen ordered while gripping his head with both hands and thrusting her hips. "I'm too horny to get any lip from you, unless it's choking on my balls!"

Ben's eyes started watering when he felt her cock going down his throat, his neck started to bulge, his chin made contact with Gwen's cantaloupe sized balls.

Gwen moans as she felt Ben's tongue running all over her cock and thrusts her hips a little faster. "Oh fuck! I never knew it could feel THIS good! Forget hands, I'm gonna start using your mouth from now on if I have a dick!" Gwen moans with ecstasy and rams her hips faster like a jackhammer.

Ben could only watch helplessly as Gwen skull fucks him with her monster cock, almost retching his jaw off from its girth, then he could taste pre leaking into his mouth. ' _It's too big!_ '

"Get ready Ben. Here. It. CUMS!" Gwen exclaimed as she gave one final thrust, she explodes inside Ben's mouth, flooding it with her ocean's worth of sperm.

"MMMMMMMM!" Ben muffly cried out when his cheeks puffed up from the sperm, some of it leaked out but a large amount flowed right down his throat, he swallowed as much as he could to prevent himself from chocking while Gwen kept pumping him full of her seed.

"Don't let it go to waste!" Gwen orders while holding her cousin's head in place.

After what felt like forever Gwen lets out a sigh and pulls her dick out of Ben's mouth, he gasped and fell on his knees slightly coughing and panting heavily for air, while sporting a semi-pot belly full of sperm.

"Hey, I said don't let it go to waste." Gwen frowned while crossing her arms.

"H-How am I...s-supposed to take it all in? I almost chocked on that!" Ben wheezed.

"Well then. I guess that means you'll have to learn how to take it easier than that." Gwen said with a smirk and then pushes Ben till he landed on his back.

"H-Hey! Gwen!" Ben said and yelped when he felt a coldness in between his ass.

Gwen was lathering Ben's crack with lube as well as her cock. "Since you took my virginity, I'll take your anal virginity~"

"Wait! It doesn't go back there!" Ben protested only to gasp when he felt her cock being pushed inside him.

"Oh, I'm sure I can make it fit Benny~" Gwen purrs while pushing her cock inside his ass. She moans to how tight his ass was around her dick while Ben was wincing as his insides were being stretched out.

"F-FUCK!" Ben cried out when he felt her cock forming a bulge under his belly.

Gwen remained still while holding onto Ben's hips and forcing his legs around her waist. His insides felt like it was crushing her cock, she swore she felt like she'd cum earlier than she expected. "Oh fuck yes! I'm gonna hollow your ass out with my huge dick!" Gwen groaned out before pulling her cock out and roughly rams it back inside. Ben gasp and yelps from Gwen's rough movements, her cock was stirring his insides while her balls smacked against his skin, his breasts flailing around from their movement and his cock bopping back and forth.

"Ah! Ah! Ah! Ah!"

"Oh, Ben! I don't know how long I've waited to do this to you, but I don't think I can hold back any LONGER!" Gwen exclaimed while pushing herself and Ben's lower body up till she's above him and ramming her cock downward. "I'm gonna keep fucking you until my balls are drained!" Gwen declared as she hammers away at Ben's ass.

All Ben could do was moan like the little bitch he was as his cousin rams her dick harder and faster inside him. Then Ben was pinned against the wall of the RV, while Gwen held him in a carry-position with his arms and legs wrapped around her and thrusting her hips upward.

"Come on, beg for it!" Gwen urged while smacking his ass cheek.

"M-M-More! F-Fuck me more Gwen!" Ben begged while pushing his breasts against Gwen.

"Louder!"

"PLEASE GWEN! FUCK ME MORE, FUCK ME OVER AND OVER AGAIN TILL I CAN'T WALK STRAIGHT!"

His cousin grinned and began hammering in so hard and fast Ben felt his ass start going numb. Then Ben was seen on his hands and knees while Gwen continued hammering away when she felt her climax reaching its limit. "I hope you're ready for another helping Ben!" Gwen grins before giving a few more hard thrusts and explodes inside Ben again.

"AHHHHHH!" Ben howled at the top of his lungs while his belly bloated to the point he swallowed a whole pumpkin from the amount of sperm Gwen pumped into him. All the while Gwen gave a small chant while her hands glowed pink and flowed into Ben.

"That's right, moan for me!" Gwen smirked while rubbing Ben's ass cheeks as the glow around her hands faded.

After what felt like an eternity she finally stops and pulls her cock out while Ben's ass quickly closes up, trapping her seed inside him. Ben panted with his eyes crossed as his own dick leaked out his seed like a dribble on the floor. He rolls on his back which spreads his boobs out and reveals his bloated belly. Gwen smiles at this and rubs his belly, feeling her seed sloshing around inside him.

"By the way you look now, you look like you're pregnant." She said while giving the belly a light smack.

"Don't...joke...about...that..."Ben gasped with his arm over his eyes.

This made Gwen gave a fox like smile before moving close to his ear. "Who said I was joking?" She whispers.

Ben glanced at his cousin with confusion and dropped his arm. "What are you talking about?"

Gwen pulls back and crossed her arms proudly. "When I was stuffing you with my spunk, I used a very special spell I found in my book, one that enables my targets to end up pregnant." She explains with a smug grin.

Ben stared at Gwen like she was crazy and shook his head. "Not funny Gwen."

"I assure you Ben I'm not joking." Gwen said while crawling over him till she's nose to nose. "As of this moment, you belong to me and only me, I won't let anyone have you or our future babies." She grouped his left boob which made him gasp and realize just how serious she is.

"B-B-But I'm a boy! I can't get pregnant, and what about these?!" Ben exclaimed while gesturing his breasts. "Everyone will think I'm a freak!"

"Oh, don't worry Benny, I'll take care of that." Gwen said before giving him a quick kiss and stood before him with her erect cock. "After all it's a fare trade. While you have bigger boobs than me, I'll have a bigger cock than you! And look at it this way Ben, you'll make a great mommy and I'll be the daddy~"

"T-That's crazy!"

"Maybe, but with time you'll grow to love your new role."

Ben only moaned in dismay while Gwen chuckled at his situation.

**(Several months later)**

Inside a bedroom were the sounds of moaning and skin smacking skin, the camera goes under the doorframe to show Gwen thrusting her cock harder inside Ben's ass, while the young lad sported a very large pregnant belly to the point his belly button was popped out. Before their grandfather came to the RV that day, Gwen used a very powerful spell she found that enabled her to alter reality itself, making it seem like Ben was born with huge breasts and was pregnant with her children. Fortunately the spell worked and no one saw them any different and Gwen kept on having her way with Ben during their summer travel.

"G-Gwen! Slow down!" Ben groaned while his leaky breasts flailed everywhere.

"I can help it Ben! No matter how many times I fuck you, you're still just as tight as you were on the first day." Gwen moans while bending forward, pulling Ben's face towards her and kissed him while groping his bust. Ben groaned while feeling more milk leak out from her grabbing. Gwen the switches Ben on his side till she has his left leg raised up and over her shoulder, and continues ramming her dick in his ass, while reaching down and rubbing his heavily pregnant belly carrying 4 almost 6 of her babies.

"You're gonna turn into a nympho after they come out, then I'll go ahead and put even more in you." Gwen grins before unleashing her seed inside Ben once more.

Ben moaned loudly as he felt more of Gwen's sperm flowing inside him, already giving him more of her babies. When she was done she lets him go, and crawls over to his boobs before latching onto his left teat. She suckled on it and drank up the milk making Ben moan with his dick staying rock hard. She pulls away from his nipple before capturing his lips, letting him taste his own milk which he swallows, before pulling away with a wet pop. "I'll let you rest up before we resume tonight, Ben. And when the time comes we'll have one big happy family~" Gwen purrs with a grin while bringing her pregnant wife close in her arms.

Ben only sighs before wrapping his arms around Gwen and nuzzles into her, accepting his new role as her wife and the mother of her children. And there was no way Gwen will ever let him go or forget who he belongs to.

**The End.**


End file.
